This is a all metal hotend upgrade kit for MK10 extruders. All metal hotend will allow you to print at a much higher temperature than the original PTFE possible. Another benefit of all metal hotend design is more consistent melting chamber control. Fused plastic creeps upward twine prints for slow extrusion speeds, PTFE solids to hotend, transition areas. In all metal designs, the transition zone is always constant, located on the right heat break. At fast extrusion speeds, PTFE tubes are correctly and not conductive enough to melt all the plastics come out. All Hotend metals are surrounded by a thermo-conductive nozzle over its length.